Dual Tires Research Articles

Stress and Strain Characteristics in Flexible Pavement Using Three-Dimensional Nonlinear Finite Element Analysis

AbstractA new numerical simulation was developed to obtain various structural parameters by employing a nonlinear finite element method using ABAQUS: stress, strain, and the displacement response of five layers on the flexible pavement. The primary purpose of this study was to develop a new simulation that can accurately and effectively characterize stress and strain problems in flexible pavement. New constitutive model equations were developed based on Hooke’s law the three-dimensional model for stress and strain. 40 kN wheel load was used to represent a set of dual tires, assuming a uniformly distributed contact area between the tire-pavement surfaced using linear viscoelastic and nonlinear viscoelastic materials. Four tire-inflation pressures were used 380, 490, 630, and 700 kPa. Results indicated that each flexible pavement layer created with a nonlinear viscoelastic material exhibited a 40% vertical plastic strain reduction compared to linear viscoelastic materials after 7000 s and repeated for 30,000 cyclic loadings. The implication of this newly developed constitutive model was verified against published experimental data. Analyses were completed to simplify the results model results considering the effects of stress and strain on flexible pavement layers. The newly developed constitutive model for solving stress and strain characterization problems can predict the effects on flexible pavement layers and various types of observed flexible pavement failure.

Mechanistic - Empirical Flexible Pavement Analysis Using Load Spectra

Prediction of pavement response based on the elasticity theory and multi-load response determined by superimposition of the tire stresses is at the heart of the mechanistic-empirical design procedure. The main focus was that the response of the pavement was modelled in such a way that tensile and compressive strains were predicted based on axle load spectra analysis for an elastic multi-layered system that was subjected to axle load spectra using a layered elastic analysis software program, KENLAYER (in conjunction with the input software LAYERINP and graphic software LGRAPH), which is part of the computer package called KENPAVE. To summarize the tensile and compressive strains results obtained for a Single Axle with Single Tire (SAST) from this study, the critical axle load magnitude for 100 kN is 226x10-6mm/mm and 237.70x10-6mm/mm respectively. For a Single Axle with Dual Tires (SADT), the critical axle load magnitude of 140kN is 243.00x10-6mm/mm and 244.00x10-6mm/mm respectively. For Tandem Axles with Dual Tires (TADT), the critical axle load magnitude of 240kN is 231.00x10-6mm/mm and 231.00x10-6mm/mm respectively. For Tridem Axle with Dual Tires (TRDT), the critical axle load magnitude of 360kN is 226.60x10-6mm/mm and 229.70x10-6mm/mm respectively. The influence of axle load range is more pronounced for TADT, followed by TRDT. On the other hand, the smallest one is SADT, and SAST is closest to TRDT.

Method of calculating the pressure on the soil of wheeled tractors

The market of tractors in Russia has changed greatly in recent years. A number of new suppliers have appeared on the market, abandoned brands are replaced for Russian analogues and machines from friendly countries. It is hard to evaluate all the quantitative and qualitative diversity of tractors provided to agricultural producers through the system of machine tests, especially considering that every manufacturer has a large number of standard size ranges of power equipment. Nevertheless, the customer should have access to information about the basic consumer properties and the degree of effectiveness of a particular machine unit. The article provides a computational method for evaluating one of the most important functional indicators of tractors, namely, the level of impact of its wheels on the soil, using limited initial information: technical characteristics and operational documentation of the manufacturer. The algorithm given in the text was approved during testing real tractor samples. Insignificant differences in the assessment of the maximum pressure on the soil, obtained as a result of measurements and calculations (the difference is 1.9-3.3 %) indicate a high degree of reliability of the developed methodology, as well as the possibility of its application in engineering practice to evaluate the functional indicators of tractors, including taking into account changes in their size and mass parameters when equipped with ballast weights, agricultural machines, implements, dual tires, etc. To make calculations, it is enough to know the weight of the tractor, the weight of ballast loads (mounted implements), the size of the installed tires, their static radius and the amount of tire inflation pressure. The methodology will significantly improve the quality of the predictive assessment of the level of impact on the soil of both mass-produced and designed tractor equipment.

Pavement responses under wide base tyres subjected to moving loads

Dual tyre assemblies are in use for heavy duty trucks since long time due to various benefits. However, under increasing pressure to accomplish more with less, truck industries have been shifting to new kind of wide base tyres called “super single tyre”. A few studies carried out to compare pavement response under dual tyre, and super single tyre have concluded that super single induce more damage to the pavement compared to the traditional dual tyres. However, most of these studies have not considered the moving loads in their analysis. The present study analyses the tyre-pavement interaction at different speeds with both the type of tyres using 3D-Move program. Results indicate that wide base tyres cause more damage in a pavement when the trucks ply at lower speeds and approximately same damage at higher speeds compared with dual tyre assemblies.

SIMPLIFIED MECHANISTIC – EMPIRICAL ANALYSIS OF FLEXIBLE PAVEMENT

Pavement stress-strain analysis is an ideal tool for analytical modelling of pavement behaviour and thus, constitutes an integral part of pavement design and performance evaluation. It is the fundamental basis for the mechanistic design theory. Predicting pavement response by simplified procedure analysis by relying on equivalency factors using axle load spectrum which is obtained from Weigh-In-Motion (WIM) data is aimed for this study. The framework for computing the structural response of the standard axle group loads on a pavement structure by using a layered elastic computer program and calculation of pavement responses for axle load distribution for different axle groups and axle types by using the theoretical analysis. From the study, the summary of the obtained results are as follows: (1) axle load distribution was developed for the four considered axle configurations; (2) Single axle with single tyre has the greatest destructive impact followed by the tridem axle with dual tyres (TRDT) and next by TADT. The least destructive axle group type is the Single Axle with Dual tyre SADT.The predicted pavement response by theoretical analysis indicates that the critical tensile strains obtained results are all greater than the critical vertical strains. At the heaviest axle load, from 70KN, for both SAST and SADT; from 140KN for TADT; and from 210KN, the critical strains have the greatest magnitude by SAST and followed by SADT and next by TADT. The least critical tensile strain is from the TRDT.

Numerical investigation on viscoelastic response of asphalt mixture under tire braking slip

A three-dimensional (3D) viscoelastic asphalt pavement, of which the surface was composed of asphalt mixture, was developed using ABAQUS and a moving 3D tire-pavement contact stress with different braking slip ratios was incorporated and programmed into ABAQUS by FORTRAN language. Five braking slip ratios were considered (Dual Tire Assembly (DTA): 0 (free rolling), 1.8%, 3.6%, 5.4%, and 7.0% (full braking); Wide Base Tire (WBT): 0 (free rolling), 1.5%, 3.0%, 4.5%, and 7.0% (full braking)). Results showed that the viscoelastic stress and strain of the asphalt mixture were significantly influenced by tire braking slip ratio and pavement temperature for both DTA and WBT loading conditions. As the slip ratio and the temperature increased, the stress and strain of the asphalt layer would increase and their positions shifted upwards to the surface of the asphalt layer. Comparatively, the peak shear strain was the most significantly influenced factor and its amplitude may increase by 10 times. However, the bottom strain of the asphalt layer was far less affected by tire breaking behaviours.

BALLASTING AND DUAL TIRES USING OF WHEELED AGRICULTURAL TRACTORS UNDER THE CONDITIONS OF FULFILLING AGRO-ECOLOGICAL STANDARDS FOR SOIL INTERACTION

The article presents an analytical approach to the implementation of ballasting and dual tires using of agricultural wheeled tractors, which is based on the unconditional fulfilment of agro-ecological standards of tires soil interaction. The necessity of harmonizing the indicators of the position of the centre of gravity of the tractor, the footprint area of the front and rear tires ratio, as well as their load capacity is shown. The need to use equal flotation in tractor’s tires during single and double use has been proven, which determines the need to maintain the position of the centre of gravity during ballasting. The method of selecting the mass of ballast weights for installation in the rear wheel discs and the front linkage system of the tractor, as well as the ballast weight system, which makes it possible to ensure the maximum possible weight of the tractor to meet the agro-ecological requirements regarding the maximum pressure on the soil, is proposed. The perspective of dual tires using to reduce the maximum pressure of the tractor on the soil is shown, and the high efficiency of ballasting the tractor on dual tires is also proven. The example shows the possibility of increasing the part of the territory of Ukraine where it is possible to operate the tractor without violating agro-ecological norms by 20-40% due to the use of dual tires. The possibility of increasing the efficiency of the tractor up to 1.5 times due to ballasting and doubling of tires has also been proven. The obtained data are based on 20 calculation variants of the tractor with different degrees of ballasting and the use of different tire doubling schemes.

Estimation and Analysis of Structural Responses of Asphalt Pavement Using Interlayer Contact Bonding Model

Interlayer contact condition of asphalt pavement has a significant impact on stress transfer and energy dissipation with adjacent layers, so a model considering with the bonding condition of adjacent layers is introduced for evaluating structural response of asphalt pavement. The pavement structure, the material characterization with temperature, the interlayer contact bonding model, the types of bond failure and prediction method of pavement life are described in detail. Results show that the transversely tensile strains at the top of asphalt pavement under the condition of high temperature were easy to cause the top-down cracking outside the dual tires edge. The bonding failure has a significant influence on strains at the bottom of the surface course with the condition of high temperature, especially, the longitudinally tensile strains would increase obviously as the disengaging area between surface course of asphalt pavement and the base layer increase. Finally, it is proved that the surface course is vulnerable to form deformations and cause damage under the combined action of low speed and high temperature.

Tyre Configuration and Axle Load of Front-Wheel Assist and Four-Wheel Drive Tractors Effects on Soil Compaction and Rolling Resistance under No-Tillage

Selecting the appropriate tyre configuration and settings for heavy farm vehicles is important to ensure that soil compaction and power loss in rolling resistance are minimised and traction is optimised. This study investigated the effect of front-wheel assist (FWA, ≈75 kN) and four-wheel drive (4 WD, ≈100 kN) tractors fitted with different tyre configurations (single, dual), tyre sizes and inflation pressures on soil strength (a proxy for soil compaction), and rolling resistance. Single-pass tests were performed on a Typic Argiudoll (≈23% clay, bulk density: 1305 kg m−3) managed under permanent no-tillage. Results showed that average power losses in rolling resistance were 7.5 kN and 5 kN for the 4 WD and FWA tractors, respectively. The average rut depth increased by approximately 1.4 times after a pass of the 4 WD compared with the FWA tractor. The soil cone index (0–600 mm depth) increased from 2023 kPa (before traffic) to 2188 and 2435 kPa after single passes of the FWA and 4WD tractors, respectively (p < 0.05). At the centreline of the tyre rut, dual tyres reduced the soil cone index a little compared with single tyres, but they significantly increased the volume of soil over which soil strength, and therefore soil compaction, was increased. For both tractors (regardless of tyre configuration or settings), soil strength increased to the full measured depth (600 mm), but relative changes before vs. after traffic became progressively smaller with increased soil depth. The power loss in rolling resistance was consistently greater with the heavier tractor, and rut depth was directly related to tyre inflation pressure.

Design of matched filter for signal‐to‐noise ratio maximization to improve data rate

AbstractThe matched filter is an optimal linear filter for maximizing signal‐to‐noise ratio (SNR) in the presence of additive random noise. Learning‐based matched filter is the proposed work. The proposed model supports (i) maximizing the SNR and (ii) setting the threshold, it is also called an intelligent matched dual tire filter. This improves the SNR by about 20 dB and the corresponding data rate to over 400 MBit/s. The bit error rate for 20 dB is very lower than FEC (10−3) of up to 10−7. The accuracy of the proposed matched learning filter is proved to be above 95%. Indoor visible light communication is one of the applications, and it can also be used for image processing and outdoor communication such as satellite and radar communication. It is obvious for communication as it avoids signal degradation, lobing, and overfitting to achieve a better data rate. This requires funding support and infrastructure facility that can be used to deploy the proposed algorithm in the real‐time scenario in the future.

Fatigue damage analysis of pavements under autonomous truck tire passes

Abstract Two different tire configurations consisting of a dual tire and a super single wide tire having different range and distribution of contact pressures have been analyzed. Along with the effect of speed on development of pavement damage at speeds of 5, 50 and 80 km h−1 under zero and uniform wander modes. Results show that at super slow speeds of 5 km h−1, at dual wheel moving at zero wander mode, decrease in fatigue life of the pavement is 3.5 years, which is 1.45 times more than the dual wheel moving at uniform wander and 3.4 times more than wide tire moving at uniform wander mode. The difference between fatigue damage at different lateral wander modes is prominent at speeds greater than 50 km h−1. A wide tire performs better than the dual wheel under zero wander configurations.

SIMULATION TESTING OF THE KhTZ-160U TRACTOR BASED ON POWERMIX FIELD CYCLES

The paper presents the results of simulation traction-dynamic tests of the promising universal tractor KhTZ-160U, obtained on the basis of PowerMix field test cycles. A technique for determining the efficiency of a tractor in an aggregate with an agricultural implement is given, which is based on the components of the power balance obtained by averaging the results of calculations for PowerMix field test cycles. Based on the results of calculating the indicators of reduced productivity, per hectare fuel consumption, the efficiency of a tractor in an aggregate with an agricultural implement and the likelihood of meeting agro-ecological requirements on the territory of Ukraine, the most promising options for equipping tractor KhTZ-160U with tires were determined. It is shown that the KhTZ-160U tractor has the best indicators of efficiency and environmental friendliness on dual tires 420/85R34 GoodYear 142 (A8), which can also carry out inter-row tillage. The base tire 480/70R34 Voltyre 143 (A8) has the worst performance and cannot be recommended for implementation, as it meets agri-environmental requirements in only 18% of Ukraine. The 540/65R34 Mitas 148 (A8) has the highest performance rating and is therefore recommended as a base.

Effect of dual and new generation wide-base tire assembly on inverted pavements

The conventional flexible pavements have been constructed such that the stiffness of the layer reduces with depth. The crust thickness becomes significantly high for heavy traffic corridors resulting in the consumption of large quantities of construction materials and also increasing environmental pollution. Inverted pavements with the aggregate interlayer (AIL) or stress absorbing membrane interlayer (SAMI) are considered to be one of the alternatives for thick conventional flexible pavements for heavy traffic corridors. The AIL or SAMI is placed between a stiff cement-treated base and asphalt concrete layer to function as crack relief layers. This change in the composition alters the behaviour of inverted pavements compared to the conventional flexible pavements. On the other hand, wide-base tires are being increasingly preferred by trucking industries due to increased fuel economy and cargo capacity. However, the effect of wide-base tires on the performance of inverted pavements is yet to be investigated. In this study, the 3D finite element (FE) models of inverted pavements considering different crack relief layers were developed, and load from dual-wheel and wide-base tires were applied. The stress-strain evolution in the various layers of inverted pavements was investigated and discussed in this study. The results indicated the higher stress and strains due to wide base tires compared to the dual-wheel assembly. Further, pavement with SAMI was found to result in lower stress and strains in the asphalt concrete layer compared to AIL pavements. • Pavement with stress absorbing membrane interlayer resulted in lower stress in asphalt layer. • Transition from compressive to tensile stress occurred at a depth of 0.66 times asphalt thickness. • Wide-base tires caused higher longitudinal stress in asphalt layer. • Confining effect of wheels due to low aspect ratio was observed for thin asphalt layers.

Creep model to determine rut development by autonomous truck axles on pavement

Abstract Impacts of autonomous truck’s passes on pavement have been analyzed in this research. Two types of lateral positioning namely zero wander and uniform wander along with a super single wide tire and a dual tire have been analyzed with variable traffic speeds in ABQUS. The study concludes with the results in favor of usage of a super single wide tire under a uniform wander mode. The highest amount of pavement damage in terms of maximum rut depth is caused by the dual wheel assembly moving under a zero-wander mode. The magnitude of rut depth increases by a factor of two when a dual tire assembly is used instead of a wide tire assembly. At a uniform wander mode, rut depth increases by 0.2 mm for every 10 km/h decrease in traffic speed within 90 km/h to 70 km/h range.

Determination of equivalent axle load factors with the use of strain energy of distortion

The paper proposes a new method for calculation of equivalent axle load factors based on the analysis of strain energy of distortion induced in road pavements by traffic loads. The main advantage of the method is the more accurate calculation of the effects of multiple axles and super single versus dual tyres. The methodconsiders the location of critical points, at which strain energy of distortion reaches extreme values. When single axles are considered, the function of equivalent axle load factor takes on the form of the well-known power equation with the exponent ranging from 2.7 to 5.3. It was proved that the damaging effect of triple axles on asphalt pavement is several times higher than the damaging effect of three single axles carrying the same load, but at a greater distance to each other. Due to this fact, traffic load may be significantly underestimated in many pavement design methods.

Soil Rut Effects on Planter Performance for Cotton in a Conservation Tillage System

Highlights Soil rutting commonly occurs during harvest and these ruts can adversely affect row crop planter performance. Four rut types were used, two formed by a tire and two formed by cutting the soil and removing soil from the ruts. Cotton seedling emergence at 15 days after planting typically was greater in unrutted soil than in rutted soil. Regression equations show a trend of decreased emergence as rut depth increased for both a sandy loam and a clay soil. Abstract. Soil rutting commonly occurs during harvest and ruts formed during harvesting can adversely affect row crop planter performance at the start of the subsequent cropping season. We conducted a three-year experiment on a sandy loam and a clay soil to investigate effects of soil ruts on the performance of a row crop planter while planting cotton into a rolled rye cover crop, and effects of planter depth setting on planter performance when planting through soil ruts. The four rut types used, prior to planting the rye cover crop in the fall, were a single tire rut, the rut from a dual pair of tires, and two rut types formed by cutting the soil 25 and 50 mm (1 and 2 in.) deep and removing soil from the ruts. The results show that although not all differences were statistically significant, for five of the six combinations of year and soil, cotton seedling emergence at 15 days after planting was greater when the soil had no rut, i.e., flat unrutted soil, than when the planter traveled across soil ruts while planting. In four of the six combinations of year and soil, emergence was significantly greater for the no rut soil condition than for a rut which was formed the previous fall by cutting 50 mm (2 in.) deep and removing soil from the rut. The three seeding depth settings used in the experiment positioned the bottom peripheries of the two disks of the double-disk opener 28, 35, and 40 mm (1.1, 1.4, and 1.6 in.) beneath the bottom peripheries of the depth-gauge wheels, providing those nominal seeding depths before the closing wheels firmed the soil. The planter depth setting did not significantly affect emergence at 15 days after planting for any of the six combinations of year and soil. Mean values of emergence at 15 days after planting in the sandy loam, averaged over the three years, were 13.9, 11.5, 12.2, 11.4, and 7.6 plants/m of row length (4.2, 3.5, 3.7, 3.5, and 2.3 plants/ft of row length) for the No rut, Single tire, Dual tire, Shallow cut, and Deep cut conditions, respectively. The means in the clay were 13.6, 5.7, 5.8, 12.6, and 7.4 plants/m of row length (4.2, 1.7, 1.8, 3.8, and 2.3 plants/ft of row length), respectively. Regression equations show a trend of decreased emergence as rut depth increased for both soils, with the clay regression line having a greater magnitude slope than the sandy loam line. Keywords: Cotton, Emergence, Planters, Planting, Seeders, Seeding, Soil ruts, Sowing.

Soil compaction in a new light: Know the cost of doing nothing – A cotton case study

Increased size of farm machinery has improved farm efficiency but at the risk of soil compaction. Here we present a novel approach investigating the effect of compaction due to in-field traffic by continuously monitoring crop canopy temperature and soil profile moisture and measuring crop yield in individual crop rows to determine the economic impact on cotton farming systems. Traffic by a tractor weighing 19.2 Mg either side of the plant row reduced lint yield by 27 % due to lower crop height, leaf area, biomass and fruit number. Elevated canopy temperature (Tc) in the compacted plots resulted in 30 % higher stress time (i.e. cumulative time when Tc is higher than the optimum Tc for cotton growth) compared with the non-compacted plots. Higher stress time in compacted plots was correlated with a 72 % and 27 % reduction in crop water use (estimated from change in soil water) at 0.3−0.5 m and 0.5 – 0.7 m depths, respectively. Water recharge in the soil profile from irrigation and rainfall was reduced by 16 % due to compaction with the highest reduction being 86 % at 0.3 – 0.5 m depth. These results demonstrate that compaction likely reduced root access to water below 0.3 m inducing water stress resulting in yield reduction. Tractors used for farm operations only compact one side of the bed, however, both sides are compacted in the absence of permanent wheel tracks. By comparison a dual tyre round module cotton picker weighing ∼32 Mg compacts 67 % of the rows on both sides and 33 % on one side suggesting greater economic loss in the following season compared to that estimated from the current study. Reductions in soil water recharge following irrigation and rainfall events due to compaction will further decrease farm efficiency and profitability. To our knowledge this is the first study related to soil compaction in any crop to show the direct relationship between yield, plant stress time and soil water dynamics at specific depths in profile. It is suggested that short term agronomic decisions (eg irrigation scheduling) need to be considered differently where compaction has been identified as limiting productivity. We recommend case studies be conducted to monitor the effect of compaction on commercial farm productivity and to demonstrate the cost of compaction across agricultural industries to drive practice change. Demonstrating the potential economic consequences of soil compaction by the integrated approach used in this study may encourage practice change to minimize compaction on farms.

Prediction of Fatigue and Rutting Premature Distress in Linear layered Flexible Pavements for Different Loading Condition using the Mechanistic-Empirical Method

The research aims to study and analyze the damage to asphalt roads and load change based on (KENPAVE) program by evaluating the performance of flexible pavement using the Mechanistic-Empirical Method (M-E). A multi-layered structure for flexible pavement was assumed with load ratios of 50%, 100%, 150%, and 200% of the standard load according to Iraqi specifications. Depend on horizontal tensile strain at the bottom of asphalt layers to estimate the fatigue failure and on the vertical compressive strain above soil layers to estimate the rutting failure. Analysis of the results showed that the highest values of vertical stress were on the single axle in the wearing layer with a value of (639.753 KPa) for standard load, and the raising of load increased the pressure distributed by the vehicle to the pavement so that the tensile and compressive strain was higher. However, the lower tensile and compressive strain values increased both (Nf and Nr). The highest tensile strain values among the layers occurred at asphalt stabilized base coarse of the single axle of (-1.5*10-4) for the standard load. While the highest compressive strain values exist at the top of the subbase layer of the single axle with dual tires of (4.761*10-4) for the standard load. It was also observed that the increasing of axle loads produces an increase in the vertical displacement of the pavement, where the deformation value on the wearing layer of the tandem axle is (0. 8998 mm) for standard load, and that (84%) of this deformation was in the subgrade layer. However, the highest value of damage ratio was existing at the asphalt stabilized base coarse with a value of (0.04426) at standard load. It was also found that the design life decreases by 9 times when increasing the load twice the standard load, which in turn reduces the paving efficiency.

Increasing efficiency of operation of agricultural tractors with double tires

The article discusses the problem of reducing the effectiveness of agricultural processes and performance indicators of a wheeled tractor with dual tires, which arises as a result of differences in the static radii of the outer and inner wheels of the tractor. Experimental tests of a wheeled tractor on dual tires using a measuring system based on a free-programmed controller “PLK-150c” are considered. Based on the results of the graphical analysis, recommendations are given to improve the performance of the operation of a wheeled tractor.

Anti-skid device weight reduction due to changes in the shape of the section of its parts

The paper discusses anti-skid device weight reduction due to changes in the shape of the section of its parts. With an increase in the design parameters of the wheels and their weight, the use of dual tires, etc., the functional properties of the engines are improved. However, tires are expensive and quickly wear out. In fact, they shall be replaced several times throughout the service life of a tractor. In terms of weight and cost, they account for about 50% of the spare parts.Currently, the best way out of this situation is to equip the wheels with quick-release anti-skid devices. Their use increases the load on the wheel, and a decrease in the anti-skid device weight optimizes the time spent for installation and removal.The functional parameters of the wheels shall correspond to the characteristics of bearing surfaces, which vary widely. The promptness of wheel adaptation to the physical and mechanical properties of surfaces improves not only the traction qualities but also the performance of the vehicle as a whole. This determines further directions of anti-skid device design development.